Synthesis and Activity of Co-doped Barium Cerium Zirconate for Hydrogen Reforming and Purification
- PDF / 151,316 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 67 Downloads / 179 Views
1126-S11-06
Synthesis and Activity of Co-doped Barium Cerium Zirconate for Hydrogen Reforming and Purification Aravind Suresh1, 2, Joysurya Basu1, Nigel M. Sammes3, C. Barry Carter1 and Benjamin. A. Wilhite1, 2 1 Department of Chemical, Materials and Bio-molecular Engineering (CMBE), University of Connecticut, Storrs, CT, 06269, USA 2 Connecticut Global Fuel Cell Center (CGFCC), UConn, 44 Weaver Road, Storrs, CT, 06269, USA 3 Metallurgical & Materials Engineering Department, Colorado School of Mines, 1500 Illinois St., Golden, CO, 80401 ABSTRACT BaCe0.25Zr0.60Co0.15O3-x (BCZC) was synthesized via oxalate co-precipitation route. Material was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Catalytic activity of BCZC with respect to hydrogen generation via methanol partial oxidation was determined. Conductivity of the material at different temperatures and under different environments was determined by AC impedance spectroscopy. XRD and TEM results indicated that BCZC was synthesized as a homogeneous cubic phase material. Catalyst tests indicated that BCZC was catalytically active towards hydrogen generation and AC impedance results were positive enough to warrant further electrochemical studies. INTRODUCTION The world today largely depends on fossil fuels for its energy needs. Questions over long term availability, geopolitical and environmental impact of these resources have driven the search for a universal, emission-free fuel derivable from both current fossil-fuel sources (e.g. coal, natural gas) and future bio-derived fuels (e.g. biogas or ethanol). Hydrogen has emerged as a promising universal energy currency – it can be derived from several fuels and converted directly to electrical energy by fuel cells thus removing the Carnot-cycle limit on combustion efficiency – for greater resource conservation. Currently the most convenient method of hydrogen generation is via oxidative reforming of high energy density liquid fuels like methanol, ethanol and butanol. By-products of gas-phase catalytic reforming reactions include carbon monoxide, carbon dioxide, methane and water. It has been reported that both carbon monoxide and dioxide by-products have a deleterious effect on the long-term operation and efficiency of proton-exchange membrane fuel cells [1, 2], thus requiring hydrogen purification in conjunction with generation. Dense thin-film membranes of palladium and various alloys (e.g., Ag-Pd, Au-Pd, Cu-Pd) have been widely used as a method of hydrogen purification [3]. However, wide-spread application of palladium-based membranes has been limited by high material costs and susceptibility to corrosion upon exposure to reforming chemistries and carbon-monoxide byproduct [4]. Recent strategies aimed at combining porous catalytic layers with dense palladium membranes have succeeded in mitigating corrosion by coupling reaction and separation in series [5] . However, designs integrating catalytic anti-corrosion films atop the palladium membrane are still limited by film instability
Data Loading...
